1. Field of the Invention
The invention pertains to hydrophones utilizing piezoelectric elements to sense sonic vibrations.
2. Description of the Related Art
Towed arrays of hydrophones are commonly used to sense underwater sonic vibrations. Such arrays are commonly used by submarines and vessels to detect the presence of other vessels, and towed arrays may also be used for geophysical purposes such as oil exploration.
Commonly, a towed array consists of a plurality of electrically interconnected hydrophones towed behind a moving vessel, such as a submarine, and the hydrophones of the array are electrically interconnected so as to produce an amplified signal. While towed arrays have been commonly employed to detect sonic vibrations in the past, existing towed arrays are subject to extraneous noise due to movement through the water and are sensitive to acceleration forces which may not be due to sonic vibration. Further, hydrophones of conventional towed arrays are expensive to manufacture, and as many hydrophones must be used in a conventional towed array which may have a length of approximately 5,000 feet, a towed array of conventional construction is very expensive.